diff options
Diffstat (limited to 'drivers/watchdog/watchdog_dev.c')
| -rw-r--r-- | drivers/watchdog/watchdog_dev.c | 300 |
1 files changed, 169 insertions, 131 deletions
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c index 3a3d8b5c7ad5..8369fd94fc1a 100644 --- a/drivers/watchdog/watchdog_dev.c +++ b/drivers/watchdog/watchdog_dev.c @@ -35,6 +35,7 @@ #include <linux/init.h> /* For __init/__exit/... */ #include <linux/hrtimer.h> /* For hrtimers */ #include <linux/kernel.h> /* For printk/panic/... */ +#include <linux/kstrtox.h> /* For kstrto* */ #include <linux/kthread.h> /* For kthread_work */ #include <linux/miscdevice.h> /* For handling misc devices */ #include <linux/module.h> /* For module stuff/... */ @@ -47,6 +48,8 @@ #include "watchdog_core.h" #include "watchdog_pretimeout.h" +#include <trace/events/watchdog.h> + /* the dev_t structure to store the dynamically allocated watchdog devices */ static dev_t watchdog_devt; /* Reference to watchdog device behind /dev/watchdog */ @@ -157,10 +160,13 @@ static int __watchdog_ping(struct watchdog_device *wdd) wd_data->last_hw_keepalive = now; - if (wdd->ops->ping) + if (wdd->ops->ping) { err = wdd->ops->ping(wdd); /* ping the watchdog */ - else + trace_watchdog_ping(wdd, err); + } else { err = wdd->ops->start(wdd); /* restart watchdog */ + trace_watchdog_start(wdd, err); + } if (err == 0) watchdog_hrtimer_pretimeout_start(wdd); @@ -171,22 +177,22 @@ static int __watchdog_ping(struct watchdog_device *wdd) } /* - * watchdog_ping: ping the watchdog. - * @wdd: the watchdog device to ping + * watchdog_ping - ping the watchdog + * @wdd: The watchdog device to ping * - * The caller must hold wd_data->lock. + * If the watchdog has no own ping operation then it needs to be + * restarted via the start operation. This wrapper function does + * exactly that. + * We only ping when the watchdog device is running. + * The caller must hold wd_data->lock. * - * If the watchdog has no own ping operation then it needs to be - * restarted via the start operation. This wrapper function does - * exactly that. - * We only ping when the watchdog device is running. + * Return: 0 on success, error otherwise. */ - static int watchdog_ping(struct watchdog_device *wdd) { struct watchdog_core_data *wd_data = wdd->wd_data; - if (!watchdog_active(wdd) && !watchdog_hw_running(wdd)) + if (!watchdog_hw_running(wdd)) return 0; set_bit(_WDOG_KEEPALIVE, &wd_data->status); @@ -231,16 +237,14 @@ static enum hrtimer_restart watchdog_timer_expired(struct hrtimer *timer) } /* - * watchdog_start: wrapper to start the watchdog. - * @wdd: the watchdog device to start + * watchdog_start - wrapper to start the watchdog + * @wdd: The watchdog device to start * - * The caller must hold wd_data->lock. + * Start the watchdog if it is not active and mark it active. + * The caller must hold wd_data->lock. * - * Start the watchdog if it is not active and mark it active. - * This function returns zero on success or a negative errno code for - * failure. + * Return: 0 on success or a negative errno code for failure. */ - static int watchdog_start(struct watchdog_device *wdd) { struct watchdog_core_data *wd_data = wdd->wd_data; @@ -261,8 +265,10 @@ static int watchdog_start(struct watchdog_device *wdd) } } else { err = wdd->ops->start(wdd); + trace_watchdog_start(wdd, err); if (err == 0) { set_bit(WDOG_ACTIVE, &wdd->status); + set_bit(WDOG_HW_RUNNING, &wdd->status); wd_data->last_keepalive = started_at; wd_data->last_hw_keepalive = started_at; watchdog_update_worker(wdd); @@ -274,17 +280,15 @@ static int watchdog_start(struct watchdog_device *wdd) } /* - * watchdog_stop: wrapper to stop the watchdog. - * @wdd: the watchdog device to stop + * watchdog_stop - wrapper to stop the watchdog + * @wdd: The watchdog device to stop * - * The caller must hold wd_data->lock. + * Stop the watchdog if it is still active and unmark it active. + * If the 'nowayout' feature was set, the watchdog cannot be stopped. + * The caller must hold wd_data->lock. * - * Stop the watchdog if it is still active and unmark it active. - * This function returns zero on success or a negative errno code for - * failure. - * If the 'nowayout' feature was set, the watchdog cannot be stopped. + * Return: 0 on success or a negative errno code for failure. */ - static int watchdog_stop(struct watchdog_device *wdd) { int err = 0; @@ -301,6 +305,7 @@ static int watchdog_stop(struct watchdog_device *wdd) if (wdd->ops->stop) { clear_bit(WDOG_HW_RUNNING, &wdd->status); err = wdd->ops->stop(wdd); + trace_watchdog_stop(wdd, err); } else { set_bit(WDOG_HW_RUNNING, &wdd->status); } @@ -315,14 +320,14 @@ static int watchdog_stop(struct watchdog_device *wdd) } /* - * watchdog_get_status: wrapper to get the watchdog status - * @wdd: the watchdog device to get the status from + * watchdog_get_status - wrapper to get the watchdog status + * @wdd: The watchdog device to get the status from * - * The caller must hold wd_data->lock. + * Get the watchdog's status flags. + * The caller must hold wd_data->lock. * - * Get the watchdog's status flags. + * Return: watchdog's status flags. */ - static unsigned int watchdog_get_status(struct watchdog_device *wdd) { struct watchdog_core_data *wd_data = wdd->wd_data; @@ -352,13 +357,14 @@ static unsigned int watchdog_get_status(struct watchdog_device *wdd) } /* - * watchdog_set_timeout: set the watchdog timer timeout - * @wdd: the watchdog device to set the timeout for - * @timeout: timeout to set in seconds + * watchdog_set_timeout - set the watchdog timer timeout + * @wdd: The watchdog device to set the timeout for + * @timeout: Timeout to set in seconds + * + * The caller must hold wd_data->lock. * - * The caller must hold wd_data->lock. + * Return: 0 if successful, error otherwise. */ - static int watchdog_set_timeout(struct watchdog_device *wdd, unsigned int timeout) { @@ -372,6 +378,7 @@ static int watchdog_set_timeout(struct watchdog_device *wdd, if (wdd->ops->set_timeout) { err = wdd->ops->set_timeout(wdd, timeout); + trace_watchdog_set_timeout(wdd, timeout, err); } else { wdd->timeout = timeout; /* Disable pretimeout if it doesn't fit the new timeout */ @@ -385,11 +392,12 @@ static int watchdog_set_timeout(struct watchdog_device *wdd, } /* - * watchdog_set_pretimeout: set the watchdog timer pretimeout - * @wdd: the watchdog device to set the timeout for - * @timeout: pretimeout to set in seconds + * watchdog_set_pretimeout - set the watchdog timer pretimeout + * @wdd: The watchdog device to set the timeout for + * @timeout: pretimeout to set in seconds + * + * Return: 0 if successful, error otherwise. */ - static int watchdog_set_pretimeout(struct watchdog_device *wdd, unsigned int timeout) { @@ -410,15 +418,15 @@ static int watchdog_set_pretimeout(struct watchdog_device *wdd, } /* - * watchdog_get_timeleft: wrapper to get the time left before a reboot - * @wdd: the watchdog device to get the remaining time from - * @timeleft: the time that's left + * watchdog_get_timeleft - wrapper to get the time left before a reboot + * @wdd: The watchdog device to get the remaining time from + * @timeleft: The time that's left * - * The caller must hold wd_data->lock. + * Get the time before a watchdog will reboot (if not pinged). + * The caller must hold wd_data->lock. * - * Get the time before a watchdog will reboot (if not pinged). + * Return: 0 if successful, error otherwise. */ - static int watchdog_get_timeleft(struct watchdog_device *wdd, unsigned int *timeleft) { @@ -540,6 +548,24 @@ static ssize_t pretimeout_show(struct device *dev, } static DEVICE_ATTR_RO(pretimeout); +static ssize_t options_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + + return sysfs_emit(buf, "0x%x\n", wdd->info->options); +} +static DEVICE_ATTR_RO(options); + +static ssize_t fw_version_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + + return sysfs_emit(buf, "%d\n", wdd->info->firmware_version); +} +static DEVICE_ATTR_RO(fw_version); + static ssize_t identity_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -611,6 +637,8 @@ static umode_t wdt_is_visible(struct kobject *kobj, struct attribute *attr, } static struct attribute *wdt_attrs[] = { &dev_attr_state.attr, + &dev_attr_options.attr, + &dev_attr_fw_version.attr, &dev_attr_identity.attr, &dev_attr_timeout.attr, &dev_attr_min_timeout.attr, @@ -635,14 +663,15 @@ __ATTRIBUTE_GROUPS(wdt); #endif /* - * watchdog_ioctl_op: call the watchdog drivers ioctl op if defined - * @wdd: the watchdog device to do the ioctl on - * @cmd: watchdog command - * @arg: argument pointer + * watchdog_ioctl_op - call the watchdog drivers ioctl op if defined + * @wdd: The watchdog device to do the ioctl on + * @cmd: Watchdog command + * @arg: Argument pointer * - * The caller must hold wd_data->lock. + * The caller must hold wd_data->lock. + * + * Return: 0 if successful, error otherwise. */ - static int watchdog_ioctl_op(struct watchdog_device *wdd, unsigned int cmd, unsigned long arg) { @@ -653,17 +682,18 @@ static int watchdog_ioctl_op(struct watchdog_device *wdd, unsigned int cmd, } /* - * watchdog_write: writes to the watchdog. - * @file: file from VFS - * @data: user address of data - * @len: length of data - * @ppos: pointer to the file offset + * watchdog_write - writes to the watchdog + * @file: File from VFS + * @data: User address of data + * @len: Length of data + * @ppos: Pointer to the file offset * - * A write to a watchdog device is defined as a keepalive ping. - * Writing the magic 'V' sequence allows the next close to turn - * off the watchdog (if 'nowayout' is not set). + * A write to a watchdog device is defined as a keepalive ping. + * Writing the magic 'V' sequence allows the next close to turn + * off the watchdog (if 'nowayout' is not set). + * + * Return: @len if successful, error otherwise. */ - static ssize_t watchdog_write(struct file *file, const char __user *data, size_t len, loff_t *ppos) { @@ -706,13 +736,15 @@ static ssize_t watchdog_write(struct file *file, const char __user *data, } /* - * watchdog_ioctl: handle the different ioctl's for the watchdog device. - * @file: file handle to the device - * @cmd: watchdog command - * @arg: argument pointer + * watchdog_ioctl - handle the different ioctl's for the watchdog device + * @file: File handle to the device + * @cmd: Watchdog command + * @arg: Argument pointer + * + * The watchdog API defines a common set of functions for all watchdogs + * according to their available features. * - * The watchdog API defines a common set of functions for all watchdogs - * according to their available features. + * Return: 0 if successful, error otherwise. */ static long watchdog_ioctl(struct file *file, unsigned int cmd, @@ -819,15 +851,16 @@ out_ioctl: } /* - * watchdog_open: open the /dev/watchdog* devices. - * @inode: inode of device - * @file: file handle to device + * watchdog_open - open the /dev/watchdog* devices + * @inode: Inode of device + * @file: File handle to device * - * When the /dev/watchdog* device gets opened, we start the watchdog. - * Watch out: the /dev/watchdog device is single open, so we make sure - * it can only be opened once. + * When the /dev/watchdog* device gets opened, we start the watchdog. + * Watch out: the /dev/watchdog device is single open, so we make sure + * it can only be opened once. + * + * Return: 0 if successful, error otherwise. */ - static int watchdog_open(struct inode *inode, struct file *file) { struct watchdog_core_data *wd_data; @@ -896,15 +929,16 @@ static void watchdog_core_data_release(struct device *dev) } /* - * watchdog_release: release the watchdog device. - * @inode: inode of device - * @file: file handle to device + * watchdog_release - release the watchdog device + * @inode: Inode of device + * @file: File handle to device * - * This is the code for when /dev/watchdog gets closed. We will only - * stop the watchdog when we have received the magic char (and nowayout - * was not set), else the watchdog will keep running. + * This is the code for when /dev/watchdog gets closed. We will only + * stop the watchdog when we have received the magic char (and nowayout + * was not set), else the watchdog will keep running. + * + * Always returns 0. */ - static int watchdog_release(struct inode *inode, struct file *file) { struct watchdog_core_data *wd_data = file->private_data; @@ -970,21 +1004,21 @@ static struct miscdevice watchdog_miscdev = { .fops = &watchdog_fops, }; -static struct class watchdog_class = { +static const struct class watchdog_class = { .name = "watchdog", - .owner = THIS_MODULE, .dev_groups = wdt_groups, }; /* - * watchdog_cdev_register: register watchdog character device - * @wdd: watchdog device + * watchdog_cdev_register - register watchdog character device + * @wdd: Watchdog device * - * Register a watchdog character device including handling the legacy - * /dev/watchdog node. /dev/watchdog is actually a miscdevice and - * thus we set it up like that. + * Register a watchdog character device including handling the legacy + * /dev/watchdog node. /dev/watchdog is actually a miscdevice and + * thus we set it up like that. + * + * Return: 0 if successful, error otherwise. */ - static int watchdog_cdev_register(struct watchdog_device *wdd) { struct watchdog_core_data *wd_data; @@ -1010,11 +1044,15 @@ static int watchdog_cdev_register(struct watchdog_device *wdd) wd_data->dev.groups = wdd->groups; wd_data->dev.release = watchdog_core_data_release; dev_set_drvdata(&wd_data->dev, wdd); - dev_set_name(&wd_data->dev, "watchdog%d", wdd->id); + err = dev_set_name(&wd_data->dev, "watchdog%d", wdd->id); + if (err) { + put_device(&wd_data->dev); + return err; + } kthread_init_work(&wd_data->work, watchdog_ping_work); - hrtimer_init(&wd_data->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); - wd_data->timer.function = watchdog_timer_expired; + hrtimer_setup(&wd_data->timer, watchdog_timer_expired, CLOCK_MONOTONIC, + HRTIMER_MODE_REL_HARD); watchdog_hrtimer_pretimeout_init(wdd); if (wdd->id == 0) { @@ -1035,6 +1073,7 @@ static int watchdog_cdev_register(struct watchdog_device *wdd) /* Fill in the data structures */ cdev_init(&wd_data->cdev, &watchdog_fops); + wd_data->cdev.owner = wdd->ops->owner; /* Add the device */ err = cdev_device_add(&wd_data->cdev, &wd_data->dev); @@ -1044,13 +1083,11 @@ static int watchdog_cdev_register(struct watchdog_device *wdd) if (wdd->id == 0) { misc_deregister(&watchdog_miscdev); old_wd_data = NULL; - put_device(&wd_data->dev); } + put_device(&wd_data->dev); return err; } - wd_data->cdev.owner = wdd->ops->owner; - /* Record time of most recent heartbeat as 'just before now'. */ wd_data->last_hw_keepalive = ktime_sub(ktime_get(), 1); watchdog_set_open_deadline(wd_data); @@ -1074,13 +1111,12 @@ static int watchdog_cdev_register(struct watchdog_device *wdd) } /* - * watchdog_cdev_unregister: unregister watchdog character device - * @watchdog: watchdog device + * watchdog_cdev_unregister - unregister watchdog character device + * @wdd: Watchdog device * - * Unregister watchdog character device and if needed the legacy - * /dev/watchdog device. + * Unregister watchdog character device and if needed the legacy + * /dev/watchdog device. */ - static void watchdog_cdev_unregister(struct watchdog_device *wdd) { struct watchdog_core_data *wd_data = wdd->wd_data; @@ -1109,15 +1145,16 @@ static void watchdog_cdev_unregister(struct watchdog_device *wdd) put_device(&wd_data->dev); } -/* - * watchdog_dev_register: register a watchdog device - * @wdd: watchdog device +/** + * watchdog_dev_register - register a watchdog device + * @wdd: Watchdog device + * + * Register a watchdog device including handling the legacy + * /dev/watchdog node. /dev/watchdog is actually a miscdevice and + * thus we set it up like that. * - * Register a watchdog device including handling the legacy - * /dev/watchdog node. /dev/watchdog is actually a miscdevice and - * thus we set it up like that. + * Return: 0 if successful, error otherwise. */ - int watchdog_dev_register(struct watchdog_device *wdd) { int ret; @@ -1133,30 +1170,31 @@ int watchdog_dev_register(struct watchdog_device *wdd) return ret; } -/* - * watchdog_dev_unregister: unregister a watchdog device - * @watchdog: watchdog device +/** + * watchdog_dev_unregister - unregister a watchdog device + * @wdd: watchdog device * - * Unregister watchdog device and if needed the legacy - * /dev/watchdog device. + * Unregister watchdog device and if needed the legacy + * /dev/watchdog device. */ - void watchdog_dev_unregister(struct watchdog_device *wdd) { watchdog_unregister_pretimeout(wdd); watchdog_cdev_unregister(wdd); } -/* - * watchdog_set_last_hw_keepalive: set last HW keepalive time for watchdog - * @wdd: watchdog device - * @last_ping_ms: time since last HW heartbeat +/** + * watchdog_set_last_hw_keepalive - set last HW keepalive time for watchdog + * @wdd: Watchdog device + * @last_ping_ms: Time since last HW heartbeat + * + * Adjusts the last known HW keepalive time for a watchdog timer. + * This is needed if the watchdog is already running when the probe + * function is called, and it can't be pinged immediately. This + * function must be called immediately after watchdog registration, + * and min_hw_heartbeat_ms must be set for this to be useful. * - * Adjusts the last known HW keepalive time for a watchdog timer. - * This is needed if the watchdog is already running when the probe - * function is called, and it can't be pinged immediately. This - * function must be called immediately after watchdog registration, - * and min_hw_heartbeat_ms must be set for this to be useful. + * Return: 0 if successful, error otherwise. */ int watchdog_set_last_hw_keepalive(struct watchdog_device *wdd, unsigned int last_ping_ms) @@ -1180,17 +1218,18 @@ int watchdog_set_last_hw_keepalive(struct watchdog_device *wdd, } EXPORT_SYMBOL_GPL(watchdog_set_last_hw_keepalive); -/* - * watchdog_dev_init: init dev part of watchdog core +/** + * watchdog_dev_init - init dev part of watchdog core + * + * Allocate a range of chardev nodes to use for watchdog devices. * - * Allocate a range of chardev nodes to use for watchdog devices + * Return: 0 if successful, error otherwise. */ - int __init watchdog_dev_init(void) { int err; - watchdog_kworker = kthread_create_worker(0, "watchdogd"); + watchdog_kworker = kthread_run_worker(0, "watchdogd"); if (IS_ERR(watchdog_kworker)) { pr_err("Failed to create watchdog kworker\n"); return PTR_ERR(watchdog_kworker); @@ -1218,12 +1257,11 @@ err_register: return err; } -/* - * watchdog_dev_exit: exit dev part of watchdog core +/** + * watchdog_dev_exit - exit dev part of watchdog core * - * Release the range of chardev nodes used for watchdog devices + * Release the range of chardev nodes used for watchdog devices. */ - void __exit watchdog_dev_exit(void) { unregister_chrdev_region(watchdog_devt, MAX_DOGS); |